Conventionally, there has been an LED module that includes light-emitting diodes, a temperature sensor disposed so that heat generated by the light-emitting diodes is applied thereto, and a protection circuit connected in parallel to a part of the light-emitting diodes (refer to a Document 1: JP 2012-133938). In the LED module disclosed in the Document 1, when a temperature sensed by the temperature sensor exceeds a prescribed threshold, the protection circuit is short-circuited so that the part of the light-emitting diodes is turned off, thereby reducing heat quantity of the light-emitting diodes.
In the above-mentioned LED module, if abnormality occurs in a function of sensing temperature, depending on a failure in the temperature sensor or the like, the protection circuit may not operate correctly, and control therefore may fall in an abnormal state.